Improvement in hoisting apparatus



l. L. ISBELL.

Hoisting Apparatus.

Patented May 6 AM PHorwumosMPH/c ca Mx (Mean/v53 mabsssg) UNITED STATESJOHN L. ISBELL, or NAUGATUOK, CONNECTICUT.

PATENT O IMPROVEMENT IN HOISTING APPARATUS.

Specification forming part of Letters Patent No. 138,655, dated May 6,1873; appll tion filed April 16,1873. 1

To all whom it may concern:

Be it known that I, JOHN L. IsBELL, of Naugatuck, in the county of NewHaven and State of Connecticut, have invented a new Improvement inHoisting Apparatus; and I do hereby declare the following, when taken inconnection with the accompanying drawing and the letters of referencemarked thereon, to be a full, clear, and exact description of the same,and which said drawing constitutes part of this specification, andrepresents, in-

Figure 1, a top View; Fig. 2, a front view with a-portion of the framebroken away; and in Fig. 3, a transverse section through the pulleys online a w.

This invention relates to an improvement in hoisting apparatus, theobject being such a construction as will automatically prevent therunning down of the fall in case of accident; and the invention consistsin a drum carrying the fall, combined with a drivingshaft provided withmeans for communicating power thereto in opposite directions, and withintermediate gearing between the said shaft and drum, whereby power iscommunicated to the drum to raise or lower the fall, the gearing whichlowers the fall being a worm and each of said gearings proportioned forequal velocity, and a slight amount of lost motion provided on one chainof gearing, all as more fully hereinafter described. I

A is the framework which supports the mechanism. B is the drum, arrangedupon a shaft, 0, and supported in suitable bearings. Upon this drum thefall D is secured, so that, by turning the drum in one direction, thefall is wound thereon, and in the other direction the fall is run ofi,in substantially the usual manner. E is the driving-shaft,preferablyarranged transversely to the shaft 0, and is supported in bearings F.Upon this shaft are two pairs of pulleys, G G and H H, one of each pair,G and H, being loose pulleys. The pulley H is securely attached to theshaft. The pulley G is attached to a sleeve, 9, through which the shaftruns, but so as to leave the pulley and the sleeve loose upon the shaft.In this sleeve is a slot, h, and in the shaft is a stud, 6, extendinginto this slot, so that the said pulley, in turning, will engage theshaft, but allow a lost motion to the extent of the slot h, for thepurpose more fu y hereinafter described. Upon the driving-j aft apinion, I, works intoa pinion, I 0 a transverse shaft, 1 connecting tothe dru l by a pinion,

I and gear 1. Power applie to the pulley G will, through this chain ofcaring, cause the drum to revolve in the dir -tion to wind up the fall,such direction bei 1 denoted by the arrow in Fig. 2. On the dri ng-shaftover the shaft 0 a worm, L, is arran f to work into a wormgear, L. 1 1

Power is applied to the pull y H to cause the worm to rotate the drum ithe opposite direction to the first-describe gearing, the rotation ofthe shaft E being; eversed, the worm being used for the lowerin of theweight. The proportion of the worm a i the pinion I to their respectivegearing is th same, so that if both sets of pulleys are firm I attachedto the shaft both chains of gearing ill be turned by means of eitherpulley. Tha such may not be the result, and that one ma 1 always be alittle in advance of the other, f the purpose of the lost motionprovided for; 1y the slot h.

It will be understood that th: 1 power is applied to but one of thepulleyat the same time, and that when the fixed i ulley of one pair isat work the belt will be on the loose pulley of the other; hence, whepower is applied to the pulley G to raise t e weight the lost motiongives it a little a vance of the worm and allows the worm to W rk freelyand without effect upon its wheel L 1 nd when the power is shifted tothe pulley 3 the lost motion in the pulley G allows the ornl to run alittle in advance, causing it to 01 rate through its wheel L. 1

When the power is working t 1 on gh the pulley G to raise the weight,sho d the power bBCOlllB disconnected, or similz accident occur, whichwould give the fall 1 I tendency to run down, the power of the fa isbrought, through the wheel L, directly n 4 a the worm; and, as thatpower cannot cause e revolution of the worm, it follows that the; escentis immediately arrested and the co sequences of such an accidentprevented, an in like manner serves as a brake to hold t load at anypoint. I have represented the poet through the pulleys, but it wil r asapplied e rcadily un- 2 neexsso derstood that other known and equivalentthrough which power is communicated in one means may be employed forcommunicating power to the shaft E.

I claim as my invention- In combination with the drum B, the two runs orchains of gearing, one of which causes the revolution of the drum towind or raise the fall, the other the revolution of the drum in theopposite direction to lower the fall, the latter by means of it worm, Lwhen the device direction is constructed to allow a slight overmotionindependent of the other device for communicating power in the oppositedirection, substantially as set forth.

J OHN L. ISBELL.

Witnesses:

J oHN E. EARLE, A. J. TIBBITS.

